This Program Project builds on knowledge gained from previous funded grants by expanding our hypotheses about the importance of early arousal and attention. It includes Subprojects that add new areas of study and risk populations, as well as extends longitudinally to school-age children. Studies include infants and children from the neonatal period through infancy, and pre-school years, up to early school-age. The design is a prospective longitudinal study of three cohorts: (1) newly recruited infants (n = 330) followed from birth to 34 months; and 2 cohorts of previously recruited infants (2) 275 followed from 34-60 months and (3) 150 children from 60 to 96 months. Adequate development of arousal and attention appears to be a necessary condition underlying normal autoregulatory development, and deficits in autoregulation will have far-reaching effects, producing problems in motor, communication and language, executive function, and cognitive organization. Based on our previous work, the relation between arousal and attention in early infancy is disrupted in systematic and differential ways by risk conditions such as acute CNS injury and neurotoxicity. Similar disruption might be expected by chronic stress in utero and genetic factors. How and when these disruptions take place, and how plasticity affects recovery, have implications for development well beyond the early infancy period, depending on the nature, timing and duration of the influence. Studying arousal, attention, and autoregulation, and how these processes are affected by different pre- and postnatal risk conditions, is fundamental to understanding a broad array of biobehavioral processes and their development, and is of major theoretical and practical importance to multiple disciplines. We propose a Project of programmatic research that is comprised of three Subprojects and one Core unit. The Subprojects study development of arousal and attention regulation related to I. Modulation of motor activity, II. Social attention and communication, and III. Executive function. The research is supported by a Testing Core. Program activities are integrated into a coherent and interactive framework. By examining the findings of individual Subprojects in relation to each other, our major goal is to generate a far richer and more accurate understanding of the mechanisms underlying the development of arousal and attention processes in both typically developing children and in those at risk for poor outcome. This will help us reach our long-term practical goal to elucidate behavioral sequelae of autoregulatory problems in high-risk infants and children.